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Journal of the Air & Waste Management Association

Yanzhi Ann Xu, Haobing Liu, Michael O Rodgers, Angshuman Guin, Michael Hunter, Adnan Sheikh, Randall L Guensler
Converting a congested High Occupancy Vehicle (HOV) lane into a High Occupancy Toll (HOT) lane is a viable option for improving travel time reliability for carpools and buses that use the managed lane. However, the emission impacts of HOV-to-HOT-conversions are not well understood. The lack of emissions impact quantification for HOT conversions creates a policy challenge for agencies making transportation funding choices. The goal of this paper is to evaluate the case study before-and-after changes in vehicle emissions for the Atlanta, GA I-85 HOV/HOT lane conversion project, implemented in October, 2011...
March 27, 2017: Journal of the Air & Waste Management Association
George M Hidy, Peter K Mueller, Samuel L Altshuler, Judith C Chow, John G Watson
It is axiomatic that good measurements are integral to good public policy for environmental protection. The generalized term for "measurements" includes sampling and quantitation, data integrity, documentation, network design, sponsorship and operations, and archiving and accessing for applications. Each of these components has evolved and advanced over the last 200 years as knowledge of atmospheric chemistry and physics has matured. Air quality was first detected by what people could see smoke and smell contaminated air...
March 23, 2017: Journal of the Air & Waste Management Association
Guixia Li, Weizhang Zhong, Rui Wang, Jiaqi Chen, Zaixing Li
Optimum anaerobic conditions of ephalosporin bacterial residues after thermal-alkaline pretreatment were determined by orthogonal experiments. And through biochemical methane potential tests (BMPs) for cephalosporin bacterial residues, the ability for bacterial degradation of cephalosporin was also evaluated. The thermal-alkaline pretreatment with the optimum values of 6% NaOH at 105°C for 15 min significantly improved digestion performance. With the thermal-alkaline pretreatment, the specific methane yield of the pretreated cephalosporin bacterial residue increased by 254...
March 23, 2017: Journal of the Air & Waste Management Association
Qingyu Zhang, Juwang Fan, Weidong Yang, Bixin Chen, Lijuan Zhang, Jiaoyu Liu, Jingling Wang, Chunyao Zhou, Xuan Chen
Vehicle deterioration and technological change influence emission factors (EFs). In this study, the impacts of vehicle deterioration and emission standards on EFs of regulated pollutants (CO, HC, and NOx) for gasoline light-duty trucks (LDTs) were investigated according to the Inspection and Maintenance (I/M) data using a chassis dynamometer method. Pollutant EFs for LDTs markedly varied with accumulated mileages and emission standards, and the trends of EFs are associated with accumulated mileages. In addition, the study also found that in most cases the median EFs of CO, HC and NOx are higher than those of basic EFs in the IVE model; therefore, the present study provides correction factors for the IVE model relative to the corresponding emission standards and mileages...
March 13, 2017: Journal of the Air & Waste Management Association
Herek L Clack
Among the technologies available for reducing mercury emissions from coal-fired electric utilities is the injection of a powdered sorbent, often some form of activated carbon, into the flue gas upstream of the particulate control device, most commonly an electrostatic precipitator (ESP). Detailed measurements of mercury removal within ESPs are lacking due to the hazardous environment they pose, increasing the importance of analysis and numerical simulation in understanding the mechanisms involved. Our previous analyses revealed that mercury adsorption by particles suspended in the gas and by particles collected on internal ESP surfaces are not additive removal mechanisms but rather are competitive...
March 13, 2017: Journal of the Air & Waste Management Association
Christopher E Rushton, James E Tate, Simon P Shepherd, David C Carslaw
Emissions of NOX by vehicles in real driving environments are only partially understood. This has been brought to the attention of the world with recent revelations of the cheating of the type approval tests exposed in the dieselgate scandal. Remote sensing devices offer investigators an opportunity to directly measure in-situ real driving emissions of tens of thousands of vehicles. The availability of remote sensing NO2 measurements are not as widely available as would be desirable. The aim of this study is to improve the ability of investigators to estimate the NO2 emissions and to improve the confidence of the total NOX results calculated from standard RSD measurements...
March 13, 2017: Journal of the Air & Waste Management Association
Yifan Xu, Rong Liu, Fei Ye, Feng Jia, Lingchen Ji
A series of MnOx-CeO2 catalysts supported by Ti-bearing blast furnace slag were prepared by wet impregnation and used for low-temperature selective catalytic reduction (SCR) of NO with NH3. The slag-based catalyst exhibited high deNOx activity and wide effective temperature range. Under the condition of NO=500ppm, NH3=500ppm, O2:7-8vol% and total flow rate=1600 ml/min, the Mn-Ce/Slag catalyst exhibited a NO conversion higher than 95% in the range of 180-260 °C. The activity of Mn/Slag catalysts was greatly enhanced with the addition of CeO2...
March 13, 2017: Journal of the Air & Waste Management Association
Jing Wang, Rongbing Fu, Zhen Xu
In this work, the effects of diatomite with 15% FeSO4•7H2O and 7.5% Ca(OH)2 on sludge stabilization were investigated using batch leaching tests. The influence of cell rupture caused by freezing and thawing on stabilization was also evaluated. The results indicated that the optimal diatomite percentage was 2%. Cell rupture by freezing and thawing reduced heavy metal leachability followed by cell death and decrease of organic groups. The concentration of heavy metals in sludge leachate increased after cell rupture, indicating that the heavy metal leachability was reduced after freezing and thawings...
March 13, 2017: Journal of the Air & Waste Management Association
Shunsuke Suzuki, Shinsuke Mori
Particle matters from a diesel engine including soot and carbon nanomaterials were collected on a sampling holder and their structure was studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). As a result of employing gas oil/ethanol mixing fuel with sulphur and ferrocene/molybdenum as catalyst sources, formation of carbon nanotubes (CNT)-like materials in addition to soot was observed in the exhaust gas from a diesel engine. It was revealed that CNT-like materials were included among soot in our system only when following three conditions were satisfied simultaneously; high ethanol fraction in fuel, high sulphur loading and presence of catalyst sources in fuel...
February 28, 2017: Journal of the Air & Waste Management Association
Y J Leong, N P Sanchez, H W Wallace, B Karakurt Cevik, C S Hernandez, Y Han, J H Flynn, P Massoli, C Floerchinger, E C Fortner, S Herndon, J K Bean, L Hildebrandt Ruiz, W Jeon, Y Choi, B Lefer, R J Griffin
The sources of submicron particulate matter (PM1) remain poorly characterized in the industrialized city of Houston. A mobile sampling approach was used to characterize PM1 composition and concentration across Houston based on high time resolution measurements of non-refractory PM1 and trace gases during the DISCOVER-AQ Texas 2013 campaign. Two pollution zones with marked differences in PM1 levels, character, and dynamics were established based on cluster analysis of organic aerosol mass loadings sampled at sixteen sites...
February 28, 2017: Journal of the Air & Waste Management Association
Ranil Dhammapala, Clint Bowman, Jill Schulte
Air quality analyses for permitting new pollution sources often involve modeling dispersion of pollutants using models like AERMOD. Representative background pollutant concentrations must be added to modeled concentrations to determine compliance with air quality standards. Summing 98(th) (or 99(th)) percentiles of two independent distributions that are unpaired in time, overestimates air quality impacts and could needlessly burden sources with restrictive permit conditions. This problem is exacerbated when emissions and background concentrations peak during different seasons...
February 23, 2017: Journal of the Air & Waste Management Association
Hong Zhang, Sheng Zhang, Ping Wang, Yuzhe Qin, Huifeng Wang
PM10 forecasting is difficult because of the uncertainties in describing the emission and meteorological fields. This paper proposed a wavelet-ARMA/ARIMA model to forecast the short-time series of the PM10 concentrations. It was evaluated by experiments using a 10-year dataset of daily PM10 concentrations from 4 stations located in Taiyuan, China. The results indicated the following: 1) PM10 concentrations of Taiyuan had a decreasing trend during 2005 to 2012 but it was increased in 2013. PM10 concentrations had an obvious seasonal fluctuation related with coal fired heating in winter and early spring...
February 23, 2017: Journal of the Air & Waste Management Association
Jorge Jimenez, Oscar Farias, Roberto Quiroz, Jorge Yañez
In south central Chile, wood stoves have been identified as an important source of air pollution in populated areas. Eucalyptus (eucalyptus globulus), Chilean oak (nothofagus oblique) and mimosa (acacia dealbata) were burned in a single chamber slow combustion wood stove at a controlled testing facility located at the University of Concepción, Chile. 2.7-3.1 kg of firewood were combusted in each experiment while continuously monitoring temperature, exhaust gases, burn rate, and collecting particulate matter samples in Teflon filters under isokinetic conditions for polycyclic aromatic hydrocarbons and levoglucosan analyses...
February 22, 2017: Journal of the Air & Waste Management Association
Zhiqiang Zhai, Guohua Song, Hongyu Lu, Weinan He, Lei Yu
Vehicle specific power (VSP) has been found to be highly correlated with vehicle emissions. It is used in many studies on emissions modeling such as the MOVES model. The existing studies develop specific VSP distributions (or OpMode distribution in MOVES) for different road types and various average speeds to represent the vehicle operating modes on road. However, it is still not clear if the facility- and speed-specific VSP distributions are consistent temporally and spatially. For instance, is it necessary to update periodically the database of the VSP distributions in the emission model? Are the VSP distributions developed in the city CBD area applicable to its suburb area? In this context, this study examined the temporal and spatial consistency of the facility- and speed-specific VSP distributions in Beijing...
February 22, 2017: Journal of the Air & Waste Management Association
Richard Derwent
The intercomparison of seven chemical mechanisms for their suitability for air quality policy formulation and assessment is described. Box modelling techniques were employed using 44 sets of background environmental conditions covering North America to constrain the chemical development of the longer-lived species. The selected mechanisms were modified to enable an unbiased assessment of the adequacy of the parameterisations of photochemical ozone production from VOC oxidation in the presence of NOx. Photochemical ozone production rates responded differently to 30% NOx and VOC reductions with the different mechanisms, despite the striking similarities between the base case ozone production rates...
February 22, 2017: Journal of the Air & Waste Management Association
Daniel Mmereki, Bontle Machola, Kentlafetse Mokokwe
Waste tyres (WTs) are becoming a significant environmental, economical and technological challenge due to their high contents of combustible composition and potential for valuable materials and energy resources. Fewer studies in developing and even developed countries have been carried out to assess the challenges regarding waste tyres management, and suggested the best alternative solutions for managing this waste stream. While developed countries made progress in waste tyres management needs by implementing more efficient innovative recovery and recycling methods, and restrictive regulations regarding the management of used tyres, in many developing countries the management of waste tyres has not received adequate interest, and the processing, treatment and disposal of waste tyre is still nascent...
February 22, 2017: Journal of the Air & Waste Management Association
Yutong Liang, Qiaozhi Zha, Weihao Wang, Long Cui, Ka Hei Lui, Kin Fai Ho, Zhe Wang, Shun-Cheng Lee, Tao Wang
Nitrous acid (HONO) is an important precursor of OH radicals in the atmosphere. In urban areas, emissions from vehicles are the main source of air pollutants including reactive nitrogen. Previously reported emission ratios of HONO (HONO/NOx) from vehicles were measured in the late 1990s which needs to be updated due to the significant changes in emission control technologies. We measured the emission ratio of a fleet of vehicles (38% diesel on average) from 11 to 21 March, 2015 in a road tunnel in Hong Kong...
February 21, 2017: Journal of the Air & Waste Management Association
Haobing Liu, Xiaodan Xu, Michael O Rodgers, Yanzhi Ann Xu, Randall L Guensler
MOVES and AERMOD are the U.S. Environmental Protection Agency's recommended models for use in project-level transportation conformity and hot-spot analysis. However, the structure and algorithms involved in running MOVES make analyses cumbersome and time-consuming. Likewise, the modeling setup process, including extensive data requirements and required input formats, in AERMOD lead to a high potential for analysis error in dispersion modeling. This study presents a distributed computing method for line source dispersion modeling that integrates MOVES-Matrix, a high-performance emission modeling tool, with the microscale dispersion models CALINE4 and AERMOD...
February 6, 2017: Journal of the Air & Waste Management Association
Long Fu, Quamrul Huda, Zheng Yang, Lucas Zhang, Zaher Hashisho
Significant amounts of volatile organic compounds and greenhouse gases are generated from wastewater lagoons and tailings ponds in Alberta. Accurate measurements of these air pollutants and greenhouse gases are needed to support management and regulatory decisions. A mobile platform was developed to measure air emissions from tailings pond in the oil sands region of Alberta. The mobile platform was tested in 2015 in a municipal wastewater treatment lagoon. With a flux chamber and a CO2/CH4 sensor on board, the mobile platform was able to measure CO2 and CH4 emissions over two days at two different locations in the pond...
February 2, 2017: Journal of the Air & Waste Management Association
Jian Kang, Junjie Liu, Jingjing Pei
This study investigates the VOCs constituents and concentration levels on a new university campus, where all of the buildings including classrooms and student dormitories were newly built and decorated within one year. Investigated indoor environments, include dormitories, classrooms and the library. About 30 dormitory buildings with different furniture loading ratio were measured. The characteristics of the indoor VOCs species are analysed and possible sources are identified. The VOCs are analysed with GC-MS method...
February 2, 2017: Journal of the Air & Waste Management Association
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